Eclipse new project (Dynamic web module) Error on creation

I want to start to learn some Java web dev. Yet I can not create a new Dynamic web module project due to this error:

Full line : Failed while installing Java 11. class org.eclipse.core.internal.resources.Project cannot be cast to class org.eclipse.core.resources.IFolder (org.eclipse.core.internal.resources.Project and org.eclipse.core.resources.IFolder are in unnamed module of loader org.eclipse.osgi.internal.loader.EquinoxClassLoader @283baa39)

I am following this beginer tutorial from vogella: https://www.vogella.com/tutorials/EclipseWTP/article.html#web-server-configuration-in-eclipse